Turbotransmission control means



2 Sheets-Sheet 2 w. AUER wunaommsmssxou comm. MEANS Filed May 20, 1938 1P 7/ I P D W Sept. 10, 1940.

w 1 z L 1 r//// 7/42 7f/ 1 k K a 4 a a u 6 7 8 3 Patented Sept. 10, 1940 r m l I UNITED STATES PATENT OFFICE TURBOTRANSMISSION CONTROL MEANS Wilhelm Auer, Heidenheim-on-the-Brenz, Germany, assignor to J. M. Voith, Heidenheim-onthe-Brenz, Germany, a copartnership oomposed of Walther Voith, Hermann Voith, and Hanns Voith Application May 20, 1938, Serial'No. 209,120.

In Germany May 28, 1937 11 Claims. (01.60-54) This invention relates to hydraulic transthe present invention, wherein the control valve missions, and in particular to control apparatus is positioned to empty both units of the-hydraulic for such transmissions. transmission. a

One object of this invention is to provide a Figure 2 isa sectional view of a part of Fi 5 control arrangement for a turbo transmission es ure 1, but with the control valve shifted to place 5 I pecially for vehicles, whereby the individual units the torque converter in operation by filling it and v of the turbo transmission may be individually to empty the hydraulic coupling. placed in and outof operation by filling or empty- Figure 3 is a sectional view similar to Figure 2, ing the respective units, the entire operation of but with the slide valve in a position wherein the filling and emptying the units being controlled. hydraulic coupling is placed in operation byflll- 10 by a common distributing valve for the entire ing it and the torque converter is emptied. turbo transmission. In general, the invention consists of a hy- Another object is to provide such a contro1 draulic transmission having a plurality of units arrangement, whereby the circuit is provided therein, such as a hydraulic coupling and a with means for filling and emptying the inditorque converter- A hy au fi i e p yin 15 vidual units, cooling the fluid and rapidly and cooling circuit is connected to these units by ying the units. this procedure ,being conway of a control valve, in such a manner that the trolled by a common distributing valve for the control Valve may be Shifted into Se l p entire turbo transmission; tions to regulate the filling and emptying of the Another object is to provide a control arran erespective units. In one position of the control 20 ent, as described above, wherein th di t valve both units of the hydraulic transmission uting valve is arranged in one position to cause are arranged to be emptied so that the vehicle the working fluid of the circuit to i m remainsat a standstill with its engine running, through a cooler for cooling therein while the yet a Portion of the Working fluid is Oirfiuleted vehicle is at a standstill with its engine running. through a e001er- 25 Another object is to provid a t 1 In another position of the controlvalve the rangement, as described above, wherein a hytorque converter is filled while the hydraulic draulic coupling and a torque converter are assoupling is emp d at the Same time a Small ciated in the transmission, and the distributing but continual fluid flow takes Place mm the valve is arranged in one position to provide a contorque Converter by y Of the distributing Valve, 30 tinual fluid flow from the tor converter t a through relatively small conduits to the cooler, cooler in order to cool the working fluid while and back through the circulating pump the the torque converter is being employed i driv. torque converter, thereby cooling the working ing the vehicle. fluid during the operation of the torque con- Another object is to provide t 1 verter. In still another position of the control rangement, as, described above, wherein while the Valve the torque, Converter i p y emptied 'O hydraulic coupling is being employed in driving its fluid by way of the control valve, through the vehicle, means is provided for rapidly emptyrelatively large conduits while the hydraulic ing the torque converter by way of the di h-1b.. coupling is filled.

o uting valve through relatively large d it During the filling of the hydraulic coupling, 40 whereas while the torque converter is being emore ve the con r l Valve is arranged to @011- ployed in the vehicle the distributing duct a. portion of the working fluid directly to valve 1 sposit1oned to permit only'a small amount the cooler, and thence back into the fluid con- Of fluid to escape from the torque o rt tainer through the operation of" the circulating through relatively small conduits. 'pump. In this manner a single control valve 45 Another object is to provide a control arrange o tr s the filling an p y of 1'lhe individment, as described above, wherein while the hyual units of the fluid transmission in a simple draulic coupling is being filled, means is provided yet rapid manner. Such a rapid emptying of the for conducting a part of the working fluid immeunits is necessary for eficient operation in the dlately Into the lfrom the pump, and thence starting and stopping of the vehicle, orin shiftbac into t e fluid container. ing from one unit to the other when the driving In the drawings: conditions change. F gure l is a d agrammatic view, mainly in Hitherto, torque converters have been provided section and showing a hydraulic transmission with an outlet opening which emptied directly control circuit according to oneembodiment of into the fluid container. With this arrangement the opening has to be sufficiently large that only so much oil can flow out of the converter into the fluid container as is necessary for the carrying away of the heat arising during the operation of the transmission. The size of this outlet opening of the torque converter may be increased only to a limited extent since with an increase in the size of the opening to which the fluid is discharged from the torque converter, a corresponding loss of energy and a consequent decrease in the chici'ency result. Nevertheless, in shifting from one unit to another it is essential that the torque con-' verter shall be emptied asrapidly as possible in order that it shall not interfere with the action of the unit being brought into operation by filling. This emptying, however, hitherto took place very slowly throughout the opening, due to its limited size on account of the above-mentioned necessity of preventing too great a loss of working fluid during normal operation.

In such prior transmissions, therefore, it frequently occurred that after the hydraulic coupling had been filled and the torque converter had been intended to be emptied, nevertheless, the torque converter still remained partially filled when the hydraulic coupling was placed in operation. This partial filling of the torque converter opposed and interfered with the operation of the hydraulic coupling and resulted in an excessively great absorption of work. Under these conditions, the driving engine was necessarily required to furnish an abnormal amount of power. Many driving engines, however, were incapable of delivering such an excessive amount of power without a corresponding reduction in speed. Consequently, during such a condition the speed of the vehicle, in changing from one unit to another, was greatly reduced. Accordingly, prior transmissions were faced with the conflicting re- 41 quirements of maintaining the outlet opening of the torque converter at a very small size during normal operation, but making them of very large size during the emptying operation. In such prior transmissions were faced with the conflicting reranged so that the fluid with the highest temperature was immediately cooled. Another requirement, therefore, is that the working fluid flowing out of the torque converter which possesses the highest temperature is conducted immediately into the cooler.

Referring to the drawings in detail, Figure 1 shows a hydraulic transmission control circuit arranged to permit idling of the driving engine while the vehicle is at a standstill. In Figure l the transmission is shown to contain a hydraulic coupling K and a hydraulic torque converter W, driven by a primary shaft P from a motor (not shown). The output of the transmission is delivered over the secondary shaft S. The hydraulic coupling K contains two blade assemblies consisting of primary and secondary rotors L and M, mounted on the primary and secondary shafts 'P and S, respectively. The torque converter W contains three or more blade assemblies, the three assemblies illustrated consisting of a primary rotor X mounted on the primary shaft P, a secondary rotor Y and a' stationary guide wheel Z. The secondary rotor Yis connected by the housing H to the secondary rotor'M, and through the latter to the secondary shaft S. Mounted upon the primary shaft P is a bevel gear p which meshes with a bevel gear it upon a shaft d which drives the fluid circulating pump D. The latter is arranged for circulating the Working fluid from the fluid container or tank 0, through the fllling and emptying circuit.

From the circulating pump D the conduit d delivers fluid by way of the control valve, generally designatedA, to the hydraulic coupling K and the torque converter W, or to the cooler B, respectively. The hydraulic coupling K ,is emptied by means of the conduit k leading from its periphery directlyinto the fluid container or tank C. The torque converter- W, however, is emptied by means of the conduit to leading to the control valve A. According to one position of the control valve A the working fluid coming from the torque converter W, through the conduit w, can be conducted through the conduit b to the cooler B, and thence through the cooler discharge conduit b intothe fluid container C for slow circulation and cooling of the working fluid during the normal operation of the torque converter W. With a different setting of the control valve A, however, the rapidemptying of the torque converter W may be obtained by conducting the fluid through the conduit w and the control valve A, through the conduit 0 leading directly into the fluid container C. For filling the hydraulic coupling K and the torque converter W the conduits k and w lead thereto, respectively, from,

the control valve A.

The control valve A consists of the stationary housing a, the main valve member a and the auxiliary valve member :1 having at the end thereof a foot portion a. The stationary housing a is divided into chambers, respectively designated I, 2, 3, l, w and k. The pump D discharges its contents through the conduit d into the chamber I of the control valve A, from the chamber 2 of which the conduit 1) leads to the cooler B. The discharge conduit 10' of the torque converter W empties into the chamber 3 of the control valve A, whereas from the chamber 4 thereof the discharge conduit 0' leads directly to the fluid container C, while from the chamber w the torque converter filling pipe w leads to the torque converter W, whereas from the chamber k the hydraulic coupling fllling pipe It leads to the hydraulic coupling K. The main valve member a is provided with annular nitches or cutaway portions 5, 6, I and 8, .together with control ports 9 and I0 therethrough. The auxiliary valve member a is provided with an annular nitch or cutaway portion H.. The above-mentioned nitches or cutaway portions constitute annular grooves in the respective valve members.

In Figures 1, 2 and 3, the flow from the pump D is indicated by full line arrows, whereas the drainage flow from the torque converter W is indicated by dotted arrows.

In the operation of the circuit with the control valve A positioned as in Figure 1, the motor (not shown) drives the primary shaft P and The secondary or output shaft S, therefore, does not rotate. The working fluid taken up by the pump D from the fluid container or tank C is conducted through the conduit d to the chamber l of the main valve'A, whence it passes through the nitch or groove 8 in the main valve member a to the chamber 2, and from there it proceeds by way of the adjustable choke b through the conduit b, the cooler B and the cooler discharge conduit b into the fluid container C. The main valve member a in the position shown in Figure 1, cuts off communication between the pump conduit :1 and the filling conduits k and W, leading to the hydraulic coupling K and the torque converter W, respectively.

Accordingly, in this standstill position of the control valve A the working fluid is prevented from passing into either the hydraulic coupling K or the torque converter W, and the working fluid is continually circulated by the pump D from the container C, through the main valve A and the cooler B, backinto the container C. The circuit is therefore provided with a ready supply of cooled fluid at the. instant starting up of the vehicle becomes necessary.

In the operation of the circuit with the control valve A in the position of Figure 2, the circuit is arranged for driving the vehicle by means of the torque conver er W. For this purpose the main valve member a has been moved downwardly one stage from its position in Figure 1, and the auxiliary valve member a has likewise been shifted to its lowest position. The working fluid pumped by the pump D through the pump conduit d discharges, as before, into the a chamber 1 of the main valve A, whence it proceeds through the groove 5 of the main valve member a into the chamber w whence it proceeds by way of the torque converter filling conduit w to the torque converter W. By this arrangement the torque converter is filled with working fluid so that it transmits a torque from the primary shaft P to the-secondary shaft S, and thence to the driving axles so that the vehicle is placed in motion.

Meanwhile, the working fluid flows through the torque converter W, where it is heated up by the action of the torque converter. .In order through the cooler and its temperature reduced.

In the operation of the circuit with the control valve A in the position shown in Figure 3,

the circuit is arranged for driving the vehicle by means of the hydraulic coupling K, the torque converter W being emptied in this arrangement. For accomplishing this the main valve member a is shifted. downwardly two stages below its position in Figure l, and one stage below its position in Figure 2. The auxiliary valve member a however, remains in the same position as in Figure 2., With this arrangement, the working fluid is pumped by the pump D, through the pump conduit d, into the chamber I, as before. From the chamber I this fluid passes through the groove 5 in the main valve member a into the chamber k whence it proceeds through the hydrauliccoupling filling conduit k to the hydraulic coupling K. In this manner the hydraulic coupling K is filled with working fluid and takes over the drive of the vehicle by transmitting the torque from the primary shaft P to the secondary shaft S. 1

Meanwhile, a part of the working fluid furnished by the pump D passes from the valve chamber I, by way of the grooves 8 and I, the

ports 9 and I0 and the groove ll of the auxiliary valve member a into the chamber 2, whence it passes through the choke b the conduit 5',

the cooler B and the conduit b into the fluidis of relatively large diameter as compared with the conduit b, as limited by the choke b hence, a rapid emptying of the torque converter W takes place inthis arrangement of the circuit.

The choke 1) serves as a throttle valve by which the discharge of fluid from the torque converter W can be regulated during the normal operation thereof so as to prevent the undue loss of energy by the discharge of an excessive amount of fluid from the converter circuit. At the same time the adjustment of the choke 11 gives a control over the cooling action of the circuit and regulates the rate at which the working fluid will be cooled. As previously stated, the cross sections of the conduits to and c are relatively large in comparison with the cross sec- 'tion of the choke b in the cooling conduit b ling the selection of said rates, and means for cooling the fluid discharged from said transmitter only at one of said rates.

2. In a hydraulic transmission circuit, a pinrality of hydraulic power transmitters, means for selectively discharging fluidefrom one of said transmitters at relatively rapid and relatively slow rates, respectively, valve means for controlling the selection of said rates, and means for cooling the fluid discharged from said transmitter only-at the relatively slow rate.

3. In a hydraulic transmission circuit, a hydraulic coupling, -a hydraulic torque converter, a source of fluid supply, a fluid distributing valve for selectively controlling the filling and emptying of said coupling and said torque converter,

a cooler, and hydraulic connections between said source, said valve, said coupling, said converter, and said cooler, said valve being arrangeable in one position to direct fluid from said source through said connections and said cooler back to said source as well as to cut oil the 'supply of fluid to said coupling and to said converter..

4. In a hydraulic transmission circuit, ayliydraulic coupling, a hydraulic torque converter, a source of fluid supply, a fluid-distributing valve,

a cooler, and hydraulic connections between said source, said valve, said coupling, said converter fluid to said converter and to direct a portion of the fluid through said cooler to said source.

5. In a hydraulic transmission circuit, a hydraulic coupling, a hydraulic torque converter, a source of fluid supply, a fluid distributing valve, a cooler, and hydraulic connections between said source, said valve, said coupling, said converter and said cooler, said valve being arrangeable in one position to direct fluid from said source to said coupling as well as to cut oil the supply of fluid to said converter, and to withdraw a portion of the fluid from delivery to said coupling for delivery to said cooler and thence to said source. v

6. In a hydraulic transmission circuit, a hydraulic coupling, a hydraulic torque converter, a source of fluid supply, a fluid distributing valve, a cooler, and hydraulic connections between said source, said valve, said coupling, said converter and said cooler, said valve being arrangeable in one position to direct fluid from said source through said connections and said cooler back to said source as well as to cut oil the supply of fluid to said coupling and to said converter and also to direct fluid directly from said converter to said source, said valve being arrangeable in a second position to direct fluid from said source to said converter and also to direct fluid from said converter through said cooler to said source as well as to cut oflf the supply of fluid to said coupling.

7. In a hydraulic transmission circuit, a hy-' draulic coupling, a hydraulic torque converter,

a source of fluid supply, a fluid distributing valve,

a cooler, and hydraulic connections between said source, said valve, said coupling, said converter and said cooler, said valve being arrangeable in one position to direct fluid from said source through said connections and said cooler back to said source as well as to cut ofi the supply of fluid to said coupling and to said converter and also to direct fluid from said converter to said source by-passing said cooler, said valve being arrangeable in a second position to direct fluid from said source to said converter and also to direct fluid from said converter through said cooler to said source as well as to cut off the supply of fluid to said coupling, said valve being arrangeable in a third position to direct fluid from said source to said coupling as well as to cut oil the supply of fluid to said converter.

8. In a hydraulic transmission circuit, a hydraulic coupling, a hydraulic torque converter, a source or fluid supply, a fluid distributing valve, a cooler, and hydraulic connections between said source, said valve; said coupling, said converter and said cooler, said valve being arrangeable in one position to direct fluid from said source through said connections and said cooler back to said source as well as to cut oil the supply of fluid to said coupling and to said converter, said valve being arrangeable in a second position to direct fluid from said source to said converter and also to direct fluid from said converter through said cooler to said source as well as to cut oil the supply of fluid to said coupling, said valve being cut off the supply of fluid to said converter, and also to direct a portion of the fluid through said cooler to said source.

9. In a hydraulic transmission circuit, a

draulic coupling, a hydraulic torque converter, a source of fluid supply, a fluid distributing valve, a cooler, and hydraulic connections between. said.

source, said valve, said coupling, said converter and said cooler, said valve being arrangeabl' one position to direct fluid from said= sbiirce through said connections and said cooler back to said source as well as to cut oil the supply of fluid to said coupling and to said converter, said valve being arrangeable in a second position to direct fluid from said source to said converter and also to direct fluid from said converter through said cooler to said source as well as to .cut oil the supply of fluid to said coupling, said 'said valve being arrangeable in one position to direct fluid from said source to said converter and also to direct fluid from said converter through sald flow restrictor and said cooler to said source, as well as to cut of! the supply of fluid to said coupling, said valve being arrangeable in another position to direct fluid from said source to said couplingiand also to direct fluid from said source through said cooler backto said source and also to by-pass fluid from said converter around said flow restrictor and said cooler to said source, as well as to cut ofl the supply or fluid to said converter.

11. In a hydraulic transmission circuit, a hydraulic coupling, a hydraulic torque converter, a source of fluid supply, a fluid distributing valve, a cooler, a fluid flow restrictor and hydraulic connections between said source, said valve, said coupling, said cooler and said flow restrictor, said valve being arrangeable in one position to direct fluid, from said source through said connections and said cooler back to said source as well as to cut of! the supply of fluid to said coupling and to said converter, said valve being arrangeable in a second position to direct fluid from said source to said converter and also to direct fluid from said converter through said flow restrictor and said cooler to said source, as well as to cut oil the supply of fluid to said, coupling, the said valve being arrangeable in another position to direct fluid from said source to said coupling and also to direct fluid from said source through said cooler back to said source and also to by-pass fluid from said converter around said flow restrictor and said cooler to 'said source, as well as to cut oil the supply of fluid to said converter.

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